1. Field of the Invention
The present invention is related to a communication base station, and in particular to a radio frequency communication base station adaptive for antenna arrays, a transceiving apparatus, a data processing system, and methods of receiving and sending data for the base station.
2. Description of Related Art
Requirements for the next generation mobile communication system have increased when compared to today's communication system. The next generation mobile communication system must be able to provide a larger variety of interactive multimedia services, such as movies, games, television broadcasts, on-line transactions and voice services, with high speed and high quality via the converged network of wired and wireless infrastructures. Such various multimedia and data services require a communications base station not only with high throughput, but also with high computation capability to handle large numbers of streams or packets simultaneously. At the same time, the base station needs to be consistent with multiple standards, and to meet the requirements of various application services. Therefore, high computation capability and enough flexibility and scalability are the trend and the challenge for communications base stations for the next generation mobile system.
FIG. 1 shows the architecture of today's base station. As shown in FIG. 1, the base-band processing system of the traditional base station includes a variety of proprietary designs implemented by semiconductor hardware in the form of a DSP (digital signal processor), a FPGA (field-programmable gate array), and an ASIC (application-specific integrated circuit), which result in different platforms serving for different standards, such as GSM (Global System for Mobile communications) and WCDMA (Wideband Code Division Multiple Access), allowing no flexibility and scalability of the whole system. In FIG. 1, the PHY layer is the physical layer, the MAC layer is the Media Access Control Layer. Even within one standard, to support different coverage and application features, the hardware platforms must also be different. In order to meet different standards and accommodate other different application characteristics, in most cases, proprietary chips of different models or quantities are required, thus necessitating the redesigning and redeveloping of the hardware platform and resulting in a high cost of time and expense. Hence, in a base station based on proprietary hardware design, the development and management cost for both hardware and software will be heavy for operators as well as for telecom equipment manufacturers.
Considering these issues for base stations built on traditional architecture, the idea of open architecture based base stations has been proposed in recent years. Under the implementation and popularization of multi-core technology, the computation performance of IT computing platforms based on general purpose multi-core processors is being increased rapidly. So as to pursue better flexibility and scalability, the industry has started to consider adopting general IT computing platforms in networking areas, thus replacing the traditional proprietary design, especially for base stations in mobile communications. Accordingly, there are some new implementations using IT servers in base station design. They can use the servers to support different kinds of standards, e.g., GSM, CDMA, and use the servers to support different numbers of sectors or cells.
From another point of view, the concept of an antenna array (a group of antenna elements) with a base station is widely used in the new generation wireless standards, e.g., 802.11n of the 802.11 series, 802.16e, TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), and LTE (Long Term Evolution). The size of the array will highly influence the throughput, coverage and system SNR (signal-to-noise ratio) of the base station. For instance, to cover a micro cell, a 2-element antenna array may be enough, but for a macro cell, a 4-element antenna array will be required. Further, different algorithms will require different numbers of antenna elements in the array. For example, 802.11n applying MIMO (multiple-input and multiple-output) technology will require an antenna array with 2 or 4 elements, while TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) using smart antenna techniques will need an array with at least 8 elements.
For traditional base station architecture composed of proprietary designs, when the size of the antenna array changes, the base band processing platform must be re-designed to accompany the changes of the antenna array. FIG. 2 illustrates the changes carried out to a base band processing platform of a traditional base station accompanying an increase in size of the antenna array. As shown in FIG. 2(a), the antenna array includes two antennas, the first antenna connected to board 0 and the second antenna connected to board 1. Accordingly, sub-channel processing hardware modules are needed in the base band processing platform corresponding to the uplink and downlink data of each antenna, i.e., an uplink sub-channel hardware module 0 to process the uplink data of the first antenna, an uplink sub-channel hardware module 1 to process the uplink data of the second antenna, a downlink sub-channel hardware module 0 to process the downlink data of the first antenna, and a downlink sub-channel hardware module 1 to process the downlink data of the second antenna. Furthermore, an uplink central processing hardware module and a downlink central processing hardware module are needed in the base band processing platform for the central main processing of uplink data and downlink data, respectively.
As shown in FIG. 2(b), when the antenna array includes eight antennas, i.e., antenna 0 to 7, not all shown, changes of the base band processing platform in hardware design must be carried out with respect to the increase in the number of antennas. Specifically, uplink sub-channel hardware modules and downlink sub-channel hardware modules, i.e., uplink sub-channel hardware modules 2 to 7 and downlink sub-channel hardware modules 2 to 7 need to be added to the base band processing platform for antennas 2 to 7. Then, the data of the added sub-channel hardware modules need to be collected into the central line boards for processing. Thus, it can be seen that for antenna arrays of different sizes, the base band processing platform needs to be re-designed and changed to correspond to the changes in the antenna arrays.
Therefore, to fulfill the required flexibility and scalability in base band processing of base stations, it will be required that the base band processing system must be able to be scaled and to have the flexibility for different sizes of antenna arrays. However, with respect to the traditional base station with proprietary architecture design, or with respect to new base station designs based on general IT servers, the scalability of antenna arrays cannot be supported using today's technology.